Method of and templet punch for stamping flat sheet metalwork



l19011.21, 1939. J s. GAY v2,180,869

METHOD 0F AND TEMPLET PUNCH FOR STMPING FLA'T SHEET METALWORK Filed March 51, 195'/ ,fg sheets-sheet 1 N0v.21,`1939. A SGA'Y 2,180,869

METHOD OF AD TEMPLET PUNCH FOR STAMPING FLAT SHEET METALWORK y Filed March 51, 193'/ 2 shets-s'heet 2 if '5,7 0"?" "9,6 "f "99 '55 y: r 1 l/ k I Patented Nov; 21', 1939 y 2,180,869 Y UNITED STATES PATENT oFFlCE IKETHOD F AND 'TEMPLET PUNCH FOB STALIPING FLAT SHEET METALWOEK Joseph S. Gay, Bualo, Y.

`Application March 31, 1937, Serhl No. 134,019 f 1o calm. (c1. 16e-1s) My invention relates to means for stamping or desired shape without resorting to the use of expunching sheet-metal material, and more particupensive tool-steel dies produced by high-priced larly to templet punches for such purposes and labor, and to employ the templet, now found to the method of stamping or punching the same. necessary to form dat sheet-metal objects in In the many industries, and particularly in the limited quantities, as part of the punching or 5 industry of manufacturing airplanes, many ilat Stamping device. ttings or parts or flat partially formed fittings Another'object ofmy invention is to provide. or parts are employed, and due to the fact that novel meansassecieted Withxe templet-die device these are not always used in lar'ge quantities and ,v fOr cushioning the action of said device and at vary in shape or form in different models oi airthe seme time utlilize the Seme t0 serve as strip- 10 planes, the cost of producing the same is exceedping means. y ingly heavy, especially when theconventional A further object is t0 prnvide n new method 0f tool-steel male and female dies are employed in punching or stampingilat sheet-metal or similar h the Stamping 0r forming of the same, Due to material, according to which the hand work now such expense, the use of regular dies are now Aresorted t0 is dispensed with when a limited 15 dispensed with and a templet formed to the exact 'quantity 0f punched 0r Stamped parts is required, shape and size of the article to be stamped, which and whereby the use 0f inexpensive tool-Steel vtemplet is used to scribe on 'sheet-metal plates Miles, nOW resorted vt0 in many industries, is enor the like, the outline of the parts to be worked tirely Obvieted.

01 fashioned to shape conformity with the The invention therefle consists in the use 0f.v

templet. used, n a templet as one of the die members of punching Assuming a few iittings or other elements of a 0r Stamping devices 0r mechanism when used kind are desired, as now generally practiced, the in esseciatien with e cO-ncting member.` 4 templet is laid upon the flat sheet-metal material The invention also consists in certain novel or other stock to be used, and the outline of the features 0f Construction and Combinati@ 0f 25 templet Ascribed upon the material or stock each parts; and in thenOVel methnd 0f manufacturing time such a fuahngior.v element isfto be made. The sheet-metal nttinss 0r parts of various lclnds or material or stock is then cut to the outline scribed shapes.` 8s described hereinafter and more parby means of hack saws, shapers, nibblers and iiles, ticularly pointedout in the sub-joined claims. for any combination ,of such machines and/or In the drawings, Fig- 'i is a rrent elevation 0f 30 tools, until the part worked upon is an exact my improved templet-punching or stamping dedupncate of the templet used as a scriber. such vice shown in ,association with two relatively methods are exceedingly slow, laborious, and exmOVabie parts 0i e punching 0r stamping press.. pensive, and call `for the employment of ex- Fig- 2S top plnn View 0f the templet-punchperienced and skilled workmanship. Where the ing 0r stamping device as it appears 0n' the bed number of parts required is comparatively small, 0f n punching er stamping pressthis method of procedure is less expensive than Fig- 3 is ntOp ple-n View 0f the male die-memthe manufacture of expensive tool-steel dies for ber 0f this imprOVed device. stamping the material or stock to the desired out- Fig. 4 iS an enlarged longitudinal section teken 40 line, or even to the exact formation desired. 0n line H, Fig. 2, showing n sheet 0r Strip 0f n The primary object of myinvention is to utilize metal interpOSed between the cio-operating die the 'templet now employed to scribe the outline members and seidA die `members in pesitien t0 vof the desired object on sheet-metal or other Stamp 8 fitting 0r Other Object .from seid Sheet 0r A sheet material, usually chrome-moly or other strip 0f metal in eOnfOrmitY With the templet hardened steel having a maximum thickness of employed as One-0f the parts 0f the die-devicethree-eighths of an inch, and herein referred to Fig. 5 is n Similar section shewing the dieas stock, as a die-member; and to provide a comembers in position afterpperntien upon the acting die-member which requires no more ex' sheet orstrip of metal.

pense tol produce than the forming of the rst Fig. 6 is a perspective view of the flat sheetelement or object when handffashioned by the metal tting stamped according to the outline of 5g use ofy 'the templet, in the manner above rethe die-members shown in Figs. 2 and 3. ferred to. Fig. 'I is a. section similar to Figs. 4 and 5, show- Another object of my invention is to provide ing an enlargement of the inventive thought insimple and inexpensive means for punching or volved, or a vmodication of the parts disclosed in stamping nat sheet-metal parts or elements to the previousngures, whereby a sheet-metal ntu ting or part having a comparatively 'large opening therein is stamped to nished form in one operation, the parts of the punching or stamping device being shown in the positions they assume preparatory to punching or stamping the sheet metal or stock to desired form.

Fig. 8 is a similar View showing the parts brought into action to stamp or punch the desired object from the sheet of metal.

Fig. 9 is a view of a sheet-metal part stamped to shape by means of the die-members illustrated in Figs. 7 and 8.

Figs. 10 and 11 are enlarged detail views on the plane of the sections shown in Figs. 7 and 8, showing respectively means for simultaneously point-punching and perforating sheet-metal while stamping the same to the desired outline, either as the finished or partly finished sheetmetal article desired. 'l

Figs. 12 and 13 are perspective views of sheetmetal parts employed in special models of airplanes, an'd which are easily and inexpensively stamped by the use of this invention.

Referring to the drawings in detail, the numeral I5 designates, for example, the bed or table of punching orstamping press, and I6 what may be termed the ram of such press; these two parts being relatively movable sand adapted to have my improved templet-punch or die-device interposed between'the two to be effectively actuated. l

The die-mechanism, or stamping device as it.

`to be stamped; but for all practicable purposesv would have a thickness notfexceeding threeeighths of an inch. y

Assuming',` for example, -thatthe stamping shown in Fig. 6 is to be-punched out of sheet metal, a counterpart of the-finished article is fashioned in any approved manner from a sheet of chrome-moly or other hardened steel, which may be twice the thickness of the material from which the fitting is to be stamped, but a templetdie one-eighth of an inch vin thickness will accurately cut chrome-moly steelthree thirtyseconds of an inch in thickness, while allowing my improved cushioning or stripping means to function efficiently. Under present-day methods, such counterpart is fashioned to'shape and used as a templet for scribing the outline upon sheetmetal stock. after which, by means of saws, shapers, nibblers, and les, or any combination of such tools and/or machines, the scribedobject is severed from the sheet-metal-stock and serves as the nished fitting or other object.

Each time such a fitting or object'is'made, v' this common method ofprocedure'is repeated,

according to my improved method, I utilize a templet of the flttingor stamping to be formed, and rivet or otherwise secure the same to a foundation plate; and when reference is made herein to a templet or templet-die or die-member, it is to be understood as meaning a part fashioned to shape from hardened sheet metal, and does not include die stock which invariably exceeds several times the thickness of the maxlmum gauge of sheet metal employed in my invention and requires the services of die-makers in order to produce the same.

In the drawings, the numeral I8 designates the templet, which I prefer to term a templet-die, and i9 the foundation plate. As shown in Fig. 3 of the drawings, two such templets are shown mounted on the foundation plate and each Is surrounded with a combined cushioning or stripping element 2D in the form of compressible rubber molded to the shape of the templet dies I8, or cut out of sheet rubber to form openings therein which conform more or less to the templet-dies. If desired, such cushioning or stripping element may be formed of several pieces of rubber disposed along various regions around the templetdie, -either in contact therewith or in close proximity thereto; and while any such type of cushioning and stripping means may answer the purpose, that believed to be most effective is the type inwhich the rubber completely surrounds the templet-die or dies, and in which the rubber Ais in contact with the edges of the die or c lies. It is preferred to have the rubber cushioning or stripping element of the same thickness as the telmplet-die I8, and this is clearly shown in Fig. 4 of the drawings.

It may here be stated that when the templetdie is machined or otherwise fashioned to shape lfrom suitable sheet material, such as chromemoly steel, it is tempered or hardened in, any approved manner; the corners formed by the upper face and the edges of the die being made shearingsharp.

The foundation plate lsand the templet-die or dies I8 serve as the mole member of the diemechanism, and the cushioning or stripping eley ment may also be considered as a part of said die'- member. It will be apparent, therefore, that the forming of the templet-die involves no more expense in time or labor than the making of the usual scribing templet employed for the purpose of Amanually fashioning fittings or stampings from sheet-metal stock; and where such a templet is lnow in existence and it is of a suitable thickness, it may be hardened and employed as the templet-die so as to form part of'themale die' moly steel, and has cut into it an opening or.

openings 2 I conforming to the shape of the tempiet-die or male die-member. When the female die-member is thus fashioned, itis also hardened, 'and the walls of the opening or openings 2|* formed therein are slightly beveled upwardly or outwardly, if desired, so as to provide clearance for the sheet-metal material which may be forced into or through said openings by the templet-die or dies. The female die-member thus formed is positioned so that the male die-member is in exact'registration with the opening or openings 2I in the female die member, and it is preferably retained in this position by a sheet metal resilient retainer strip 22 which is welded or other- Swise secured to the under-side of the at female aisasee die-member, as at 23, and distantly therefrom to the foundation plate I3, as at 24. This yielding retainer strip is comparatively thin, yet provides the necessary rigidity to maintain the female diemember in proper registration with the male ldiemember. It nevertheless may be said to serve as a' flexible connection between the female diemember and the foundation plate I9.

The female die-member has a handle or fingergrip extending therefrom opposite the yielding or flexible retainer strip 22, and by means of this handle or finger-grip the female die-member 'may be elevated to permit the ready introduction of a strip or sheet of metal or other stock from which the nttings or other elements are to be stamped to be freely inserted between the two die members; and for the purpose of preventing the female die-member from being moved out of registration with the male die-member, it is providedwitlra guide-opening 26 in the handle or nger-grip which receives a guide-pin 21 extending upwardly from the foundation plate I3. This guide-pin may be of sufficient length to enable the female die-member to be elevated under fiexure of the yielding retainer-strip 22 without withdrawing the guide-pin 21 from the opening 26. Thus elevated, the sheet-metal or other stock may be easily inserted between the flat female die-member and the upper face of the-tempietdie or dies I8. also referred to as a die-member.

, It is of course to be understood that although I have shown two tempiet-dies in the construction illustrated in Figs. 2 and 3, and two openings in the female die-member to co-act with the templet-dies, this may be found of advantage only where the ttings or stampings are comparatively small, or where they differ in shape and occupy comparatively small space.

While the templet-dies shown in Fig. 3 are of somewhat similar outline, they vary in measurement. Consequently, two different fittings or stampings are produced under one operation of the press.

I desire here to state that the forming of the openingsin the female die member is a simple and inexpensive operation as compared to the making of heavy dies out of tool-steel; and as this is the only particular machine operation resorted to in addition to using the ordinary tempiet and converting it into a tempiet-die, it will be clear that this die-mechanism is extremely compact and inexpensive. Its compactness results from the fact that only sheet-metal stock is employed, and if desired, the foundation plate may even be dispensed with and theftemplet-die pinned or otherwise secured directlyto the bed or table of the press.

While a punching or stamping press is considered the most efficient means of operating the die-mechanism, stamping may be effected by any other means, especially when small fittings or the like are to be stamped from sheet-metal, such as positioning the die-mechanism between the jaws of a vice, or other similar device or apparatus. It is of c ourse essential that the tempietdie I8 and its surrounding cushion 20 be thicker than the material 4fromwhich the fittings or Vother stampings are to be punched, as will be clear from the disclosures made in Figs. 4 and 5. In Fig. 4 the sheet of metal 28 is shown between the tempiet-die or male die-member and its surrounding cushion and the female die-member 2|, without pressure being exerted lon either the male or female die-member. However, in Fig. 5, the female die-member is forced downwardly so cushioning and stripping element 20a.

that the tempiet-die I3 is entered slightly in the opening 2|* formed in the female die-member,

causing the shearing of the sheet metal 23 with an outline exactly that of the tempiet-die I3; that portion of the sheet metal overhanging the tempiet-die and lying upon the cushioning element 20 being forced downwardly around the tempiet-dies by the female die-member, with the result that the cushion 20 is compressed and laterally distended, as clearly shown by comparison between Fig. 5 and Fig. 4. Thus the sheet-metal fitting or other stamping enters the opening in the female die-member and can be removed therefrom after relieving the female die-member of pressure, caused for example, by elevating the ram v||l of the press. The sheet- Vmetal thus stamped will automatically retain its position on the tempiet-,die while the cushioning element 23 retrieves its normal condition" and formation, acting to strip the surrounding portion of the sheet metal from the tempiet-die. There` lfore, relieving pressure from the female die-member in the manner hereinbefore stated, the stamped fitting may easily be removed from between the two die-members, and the sheet-metal 23 advanced through the die-mechanism so that an unstamped portion thereof is positioned over the tempiet-die or dies for further action.

In Figs. '7 and 8 I have illustrated -an enlargey ment of my inventive thought by means of which fittings' and other stampings having openings therein may be punched out of sheet metal or other sheetmaterial, a fitting of this kind being illustrated in Fig. 9 wherein the particular object Vshown is aldoor frame 29 adapted to be fastened and surrounding said tempiet-die in spaced relation thereto is an auxiliary tempiet-die |8b; the

' space 33 between said tempiet-dies |8 and |8b;

being occupied, or partly occupied by a combined Y I prefer in this die structure, which I term a double-action die, to provide a header-plate 34 which is also constructed of sheet-metal and has formed therein an opering 35 approximating the Vshape of the tempiet-die IBI. To the underside of said header-plate 34 a tempiet-die 36 is secured by welding, riveting, or otherwise fastening it thereto. This tempiet-die isprovided with an opening 31 conforming to the tempiet-die Iiia so that the two co-act with a shearing effect, and the formation of the -tempiet-die 36 is such that it will enter the intervening space 33 between the tempiet-dies I8 and I3b under shearing action.

vSurrounding the tempiet-die 36 is a combined cushioning and stripping element 38.

The die-member 32, which may be referred to as the upper die-member, may have laterally extending handles or finger-grips 25asimilar to thatA tained in co-acting relation with the templet-dies of the lower die-member, and the upper diemember may be easily elevated von its guide pins l0 to enable a sheet oi' metal or other stock 28 tovbe interposed between the two, the metal or stock resting on the lower 'die-member and supporting the upper die-member.

When placing the upper die-member under pressure in any approved manner suitable for the purpose. the templet-die 38 of said die-member is forced into the space 33 of the lower diemember, causing the cushioning or stripping element 2lil therein to be compressed and laterally di'stended, as shown in Fig. 8, .while the templetdie I8* is forced into the opening 31 in the templet-die 36 and the auxiliary templet-die il of the lower die-member is forced upwardly around the templet-die 38 on the under-side of said upper die-member, causing the cushioning or stripping element 38 to be compressed andlaterally distended, as shown in Fig. 8. Thus the sheet metal or other stock is sheared to form the door frame 29 and separates from the stock a portion of the metal in the region 4i so as to form the opening 30 of the door frame. Upon relieving the die-members of pressure, the cushioning and stripping elements 20e and 38 immediately ex- Dand to cause the twodie-members to return to their normal positions, as indicated in Fig. 7. Upon elevating the upper die-member on its guide pin 40, the severed portion 4I and the door frame may be easily removed from between the y die-members and the stock advanced to position an unstamped region between the die-members for stamping an additional door frame. It is of course understood that the stock removed from the material being stamped to form the opening 30 in the door frame may be utilized for stamping Asmall fittings or other elements, such as shown is provided with spaced-apart point-punches;.

and, when such features are desired to be added to the article being stamped, one of the templetdies, for example the templet-ldie 36, is provided with point-punches 42, as shown in Fig. 10; each of such point-punches being provided with a conical lower terminal 43 whose length is less than the thickness of the material being punched.

The point-punches are .positioned directly over the cushioning or stripping element 20e and are fixed vinto the templet-die 3B in the spaced relation desired. In some instances a single pointpunch only will be required. The point-punch shown in Fig. 9 may determine the location of attachment of other parts to the door frame, or it may be used for various other purposes, such as indicating a point at which drilling of the door frame is required.

' In the construction shown in Fig. 1l, the cushioning or stripping device 20 may be formed in two spaced-apart sections, 20", or this cushioning or stripping device may be provided with openings at spaced-apart regions where punch holes are to be formed in the door frame or other object, and in such cases4 a perforating punch 44 is fastened into the templet-die 38 and extends a suflicient distance below the lower surface thereof so as to completely penetrate the stock where the sections 20h of the cushioning element 20* are spaced apart or provided with openings. It will be clear, therefore, that punch holes may be provided in a stamped element simultaneously with the formation of the element.

In Fig. l0 the construction shown is that which is preferable when the two sections 'i0b are provided in spaced-apart relation, since upon compression oi the cushioning or stripping device, the rubber sections forming the same may be distended in opposition to each other, while being compressed: whereas, if openings are formed in the cushioning or :stripping device directly beneath the punches M, I would form said cushioning or releasing device to occupy only a portion of the width of the space 33 in which it is fitted. l

In Fig. 12 a special fitting 45 is shown which is used on an airplane in flat form, and in Fig. 13 a special fitting 48 is illustrated which may requirebending when applying the same to a part of an airplane. The several fittings or stampings shown are merely illustrative of the innumerable varieties of fittings or stampings that are used in various industries, and therey fore the advantages of this invention are far reaching and result in a tremendous savingin the production of stampings of various kinds, since, if a thousand or less stampings of any kind are required, the die-mechanism shown can be constructed and the stampings made therefrom in less time and at a small fraction of the expense required in providing the usual tool-steel dies, the use of which is now resorted to in many industries, even though stampings or fittings are required in comparatively small quantities.

I particularly desire to stress the fact that the templet-dies are allused in hardened form, and vthey are fashioned to the desired outline or shape while the stock from which they are made is more or less ductile and therefore easily workable, after which such templet-dies may be annealed in any approved manner.

In the manufacture of airplanes and other machines, apparatus, andi articles, many are formed to the individual specications of the purchaser and a comparatively small number ordered at a time; the drawings and specifications for the same demanding special metallic fittings or elements which would not warrant the Aexpense of making steel-cut or similar dies. Consequently, in many instances, a templet of the desired fitting or element is made and is employed to scribe the outline of the same upon metal or other stock from which the litt-ing is to be made. Each individual fitting is then required to be cut out of the stock, and foi-this purpose saws, Shapers, nibblers, and files are used to complete the same; such fittings or elements requiring the same degree and exactness of work as the forming of the scriber-templet. Consequently, a fitting of which fifty exact counterparts are required is expensive to produce under such methods; but in the absence of a more efficient method, such methods are now employed. Manifestly, the form of a simple templet, properly hardened and used as a templet-die in the manner described, requires only th formation of a interiltting associate/part, or two interfitting associate parts'where an article is to be formed in which a comparatively large opening is provided therein. With the exception of orders were unexpectedly given by the purchaser..

a comparatively large number of such fittings y .were required which would ordinarily be stamped with dies cut from tool or other suitable steel by die makers; but having had the templet-dies prepared for the trial orderthe large quantity later used was made with the same templet-dies as efficiently and effectively as though regulation tool-steel dies were employed. I am aware that it is not new to employ a comparatively thin die-member and use the same in opposition to a rubber or other cushioning bed, but these are only suitable for stamping thin sheets, such as tin or lead foil, paper and the like; and where even soft sheet material is to be stamped with the use of a rubber or other cushioning element employed as a press member, the actual die-member must be of a thicknessconsiderably greaterl than possible to form out of sheet-metal. Consequently, die m e c h a n ism which includes a rubber element employed in opposition to the actual die calls for a die of va thickness requiring the services of die makers, since the'die must receive the rubber co-acting element deply into or around the actual die before shearing of the soft sheet-metal can take place, and a press so large and powerful would be required that the use of such stamping mechanism would be valuable only to comparatively few plants'. .i

My invention therefore differentiates over methods in which a bed or cushioning element co-operates with a die-member in stamping material; and with such stamping mechanism, re-

gardless of the method used, chrome-moly or .i

other hardened steel cannot be stamped to form, since only indentation of the metal will take place.

Where, therefore, in the claims reference -ls made to a sheet-metal templet, templet-die or die-member, or sheet-metal part, it is intended to -mean hardened sheet-metal'parts not employed sheet material, and the employment of a sheet-` metal part co-acting with said templet to shear the material in conformity with the shape of said templet under the application of pressure causing relative movement of said templet and sheet-metal co-acting part.

2. The method of punching or stamping sheetmetal fittings or lthe like from sheet material, comprising the forming of a hardened sheet-metal templet and the utilization of the same as a die in association with a compressible cushioning element adjacent said die and with a co-acting sheetmetal partarranged in shearing relation to said die so as to compress said cushioning element, and in the employment of suiiicient power to move said die andshet-metal part relatively to cause shearing of sheet-metal material placed between the two in conformity with the shape of said die.

3. Die-mechanism for punching or stamping at sheet metal, comprising a fiat sheet-metal templet-die thicker than the thickness of the sheet metal to -be punched or stamped thereby a flat sheet-metal element having an opening therein conforming to that of the templet-die and positioned in relation to the latter that a sheet of metal may be placed between said templet-die and fiat sheet-'metal element, and means for relatively moving said templet-'die and flat sheetmetal element.

4. Die-mechanism for punching or stampln at sheet metal, comprisinga fiat sheet-metal templet hardened and utilized as a die-member, said templet being shaped in conformity with the article to be stamped, a sheet-metal member co-acting with said templet and constructed to cause shearing of stock placed between said templet and said co-acting sheet-metal member in conformity with-the outline of said templet, said templet and co-acting sheet-metal member being relatively movable and arranged to permit the introduction of stock to be punched or stamped between the two. and stripping-means surrounding said templet and yieldabe under movement of said co-acting element in one direction and selfretrlevable to release the stock from said templet when moved in its other direction.

5. Die-mechanism for punching or stamping .flat sheet metal, comprising a fiat sheet-metal with the article to be stamped and being mounted on a fixed support, a sheet-metal element serving as the female die-member and constructed to receive the male die-member thereinto. said female die-member being secured to a movable pressure or power element, and rubber cushioning means surrounding said male die-member compressible under movement' of said female diemember during the act of punching or stamping sheet material placed between the latter and said male die-member, said cushioning means being self-retrievable upon relieving said female diemember of force.

6. The combination with a suitable foundation and a power medium, of die-mechanism having co-acting die-members formed of sheet metal not exceeding one-quarter inch in thickness to enable their being lfashioned to shape'with means employed to fashion a sheet-metal templet, one of said die-members being mounted on said 'foundation and the other being adapted to be actuated by said power medium, said die-members being relatively disposed to permit hardened sheetmetal to be punched or stamped to be introduced therebetween, the die-member mounted on said foundation being of a thickness greater than that of the stock to be punched or stamped, and a rubber cushioning-element surrounding the lastmentioned die-member and of a thickness substantially equaling that of the latter.

7. Die-mechanism comprising two die-members formed of flat sheet metal relatively movable and adapted to have sheet metal to be stamped or sheared to form placed between the two, one of said die members compriiging a foundation member having a guide-pin projecting therefrom and a die portion mounted thereon. the second diemember comprising a at plate having an opening therein conforming in shape to the die portion oi' said first-mentioned die-member and provided with a guide-opening through which said guide-pin extends, and a resilient retainer-strip secured to said second die-member and to said foundation member at a point spaced from said second die-member.

8. Die-mechanism comprising twodie-members formed of fiat sheet metal and being relatively movable and adapted to have sheet-metal to be stamped or sheared to form placed between the two, one of said die-members comprising a sheetmetal foundation plate. the other die-member being formed of sheet-metal having a die-receiving portion therein to receive said templet-die, and meanstoexibly connect said last-mentioned die-member with said foundation plate.

9. Die mechanism comprising co-acting sheet-i metal die-members between which sheet metal to be stamped is to be positioned. a rubber cushioning elementin the plane of movement of one of Y tact with the peripheral edge ci said templet-die at all points around the same, a sheet-metal diemember positioned directly over said cushioning element and adapted to receive said templet 'thereintm and punches projecting from said i'emale die-member adapted to act upon the sheetmetal above said cushioning element. y

JOSEPH B. GAY. 

